McDonald's Corp has been sued by a woman who said her two-year-old son ate a used condom he found in the play area of one of its restaurants in Chicago.

Anishi Spencer filed the complaint against the fast-food restaurant chain on Wednesday in Cook County Circuit Court on behalf of herself and her sons, Jonathan Hines and Jacquel Hines.

According to the complaint, Spencer and her sons were at a McDonald's restaurant in Chicago's South Side on February 4, 2012 when Jacquel picked up the used condom from the floor, and shortly thereafter coughed up a piece of it.

Both boys required medical care, and have suffered lasting injuries, pain and discomfort, the complaint said.

Spencer accused McDonald's of negligence for failing to clean hazardous debris from the play area, and failing to use appropriate security measures to help uncover "deviant activities." The lawsuit seeks at least $50,000 of damages.

"This is a very disgusting case," Jeffrey Deutschman, a lawyer for Spencer and her sons at Deutschman & Associates in Chicago, said in a phone interview.

He said he tried to settle, but was unable to do so after having to deal with "layers and layers" of bureaucracy at McDonald's, which is based in Oak Brook, Illinois.

McDonald's spokeswomen did not immediately respond to requests for comment.